Known intrusion detection systems include a plurality of sensors in a plurality of zones to protect a secured area. When an authorized person enters the secured area, each of the plurality of zones in the secured area is disarmed. However, an unauthorized person may intrude the secured area by tailgating the authorized person into the secured area without the knowledge of the authorized person. Unfortunately, known intrusion detection systems will not detect a presence of the unauthorized person and identify an alarm state responsive thereto because the secured area is disarmed responsive to the entrance of the authorized person. Accordingly, known intrusion detection systems will not notify the authorized person about the potential threat of the unauthorized person. Furthermore, the authorized person may ignore the unauthorized person in the secured area because the authorized person may incorrectly assume that the unauthorized person is authorized to be in the secured area.
In view of the above, there is a continuing, ongoing need for improved systems and methods.